Method readField

pdal/DbWriter.cpp:178–229

Read a field from a PointView and write its value as formatted for output to the DB schema to the location as requested. \param[in] view PointView to read from. \param[in] pos Location in which to store field value. \param[in] id ID of the dimension to read. \param[in] idx Index of point to read. \return Size of field as read.

/// \param[in] idx      Index of point to read.
/// \return  Size of field as read.
size_t DbWriter::readField(const PointView& view, char *pos,
    Dimension::Id id, PointId idx)
{
    using namespace Dimension;

    DimType& dt = m_dimMap[(int)id];
    size_t size = Dimension::size(dt.m_type);

    // Using the ID instead of a dimType as the arugment hides the complication
    // of the "type" of the dimension to retrieve in the case of location
    // scaling.
    view.getField(pos, id, dt.m_type, idx);

    auto iconvert = [pos](const XForm& xform, Dimension::Id dim)
    {
        double d;
        int32_t i;

        memcpy(&d, pos, sizeof(double));

        d = xform.toScaled(d);
        if (!Utils::numericCast(d, i))
        {
            std::ostringstream oss;
            oss << "Unable to convert double to int32 for packed DB output: ";
            oss << Dimension::name(dim) << ": (" << d << ").";
            throw pdal_error(oss.str());
        }
        memcpy(pos, &i, sizeof(int32_t));
    };

    if (m_locationScaling)
    {
        // For X, Y or Z.
        if (id == Id::X)
        {
            iconvert(m_scaling.m_xXform, Id::X);
            size = sizeof(int32_t);
        }
        else if (id == Id::Y)
        {
            iconvert(m_scaling.m_yXform, Id::Y);
            size = sizeof(int32_t);
        }
        else if (id == Id::Z)
        {
            iconvert(m_scaling.m_zXform, Id::Z);
            size = sizeof(int32_t);
        }
    }
    return size;
}


/// Read a point's data packed into a buffer.